Controller Responsive To Variation In Pressure In One Source For Varying Pressure In Another Source

Abstract

A controller having an integral element including two flexible diaphragms forming, with a casing, two separate chambers, one of the diaphragms having a larger pressure-subjected area than the other. One of the chambers is connected to a motivating source of fluid and the other is connected to a motivated source of fluid. A spring is connected to one of the diaphragms and the force of the spring is controlled.

Description

CROSS-REFERENCE TO RELATED APPLICATION

The controller of the present invention is an improvement over the controller shown in the inventor's copending application Ser. No. 731,842 filed May 24, 1968 in Group 284, now U.S. Pat. No. 3,545,276

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention is directed to fluid actuated controllers of the type in which variations in pressure in one chamber of the controller is utilized to vary the pressure in another chamber of the controller.

2. Description of the Prior Art

The prior art controllers employing two diaphragms of different areas exposed to pressures are the U.S. Pat. to Bialous et al., No. 2,883,995 and the French Pat. to Thuru, No. 1,057,817. Neither of these patents shows an integral element which forms two diaphragms with a spring interposed between the diaphragms, which spring is adjustable for varying the pressure exerted thereby on one of the diaphragms. In the present invention, the spring and the adjustment therefor is external of both sources of pressure.

SUMMARY OF THE INVENTION

The controller of the present invention comprises two chambers which are separated from one another by a unitary element forming two flexible diaphragms. The unitary element includes a spacing portion between the diaphragms. One of the diaphragms is subjected to a different quantity of fluid than the other and has a larger area exposed to one of the fluids than the area of the other diaphragm which is exposed to another quantity of fluid. A spring and an adjustment therefor are disposed intermediate the diaphragms and exterior of both fluids.

Other features and the advantages of the present invention will be apparent from the following description, reference being had to the accompanying drawing wherein a preferred embodiment of the invention is illustrated.

BRIEF DESCRIPTION OF THE DRAWING

FIG. 1 is a side view of the controller;

FIG. 2 is a sectional view taken along line 2--2 of FIG. 1, but on a larger scale; and

FIG. 3 is a sectional view taken along line 3--3 of FIG. 2.

DESCRIPTION OF THE PREFERRED EMBODIMENT

The controller 10 includes a casing 12 which is formed of a ring 14 and two cups 16 and 18. The interior surfaces of the cups are sealingly connected with the periphery of the ring in any desired manner. For examples, if the ring and cups are formed of metal, they may be connected by welding, by screws, etc.; or if the ring and cups are formed of plastic, they may be glued together, as by an epoxy. One side of ring 14 includes an inwardly extending portion 20. The interior of cup 18 is provided with a circular shoulder 22.

Cup 16 is provided with a nipple 24 which is threaded for connecting the same with a tube 26 containing a fluid. Cup 18 is provided with a nipple 28 which is threaded for connecting the same with a tube 30 containing a separate fluid.

An element 32 forms two flexible diaphragms 34 and 36. This element is formed of flexible material such as rubber or synthetic rubber. The diaphragms include circular corrugations 38. The element 32 includes a centrally disposed spacer portion 40. Thus the element is unitary, providing the diaphragms 34 and 36 and the spacer portion 40.

The inwardly extending portion 20 of the ring 14 is provided with an outwardly extending circular groove 42, and the opposite side of the rim is provided with a circular groove 44. The outer portion of diaphragm 34 includes a circular bead 46 which is received by the groove 42. The outer portion of diaphragm 36 is provided with a bead 48 which is received by the groove 44. The ring 14 and the element 32 form a unit 50 since the element is held in position by the flexible interrelationship between the beads 46 and 48 and the surfaces forming the grooves 42 and 44, that is, the diaphragms are biased toward one another. Obviously, if desirable, the diaphragms can be fixed to one another by glue between the beads and the surfaces forming the grooves.

The cup 16 and diaphragm 34 form a closed circular chamber 52 and the cup 18 and the diaphragm 36 form a closed, circular chamber 54. The confronting walls of diaphragms 34 and 36 and the ring 14 form a chamber 56 intermediate chambers 52 and 54. Chamber 56 is open to the environment by a hole 58 in the ring 14.

It will be observed that the diaphragm 36 is larger in diameter than the diaphragm 34. Therefore, the area of diaphragm 36, which is exposed to the interior of chamber 54, is greater than the area of diaphragm 34, which latter area is exposed to the interior of chamber 52. Consequently a variation in pressure in chamber 54 will cause a greater differential in pressure in chamber 52, i.e., should the pressure in chamber 54 increase, a proportionately greater pressure will be increased in chamber 52, and vice versa. This differential in fluid pressure is of particular value in such system as shown in the copending application aforementioned.

A spring, such as leaf spring 60, engages one of the diaphragms herein shown as engaging a shoulder 62 on diaphragm 36. The spring 60 is provided with portions 64 which straddle the connecting portion 40 for the diaphragms 34 and 36. The portions 64 merge with a portion 66 which merges with a loop 68, which in turn merges with an angling portion 70. The loop 68 receives a pin 71 for pivotally supporting the spring 60.

The force value of the spring 60 is adjustable by a screw 72. This screw is threaded into the ring 14 and it engages the angling portion 70 of the spring.

From the foregoing it is apparent that by virtue of the present invention, I have provided an inexpensive controller which is readily adjustable from the exterior of the casing for the controller. The adjustment, including the spring 60 and screw 72, is exterior to the chambers for the fluid, thus eliminating leakage between the chambers and the environment.

Claims

Having described my invention, I claim:

1. A controller for varying the pressures between a motivating fluid and a motivated quantity of fluid, said controller comprising in combination:

A. a casing having:

1. an inlet opening,

2. an outlet opening;

B. a tube connected with one of said openings in the casing;

C. a tube connected with the other opening in the casing;

D. an integral element carried by the casing, said element having:

1. two flexible diaphragms cooperating with the casing to form two closed compartments that are isolated from one another, one of said compartments being connectable with the motivating fluid through one of said openings in the casing and the other compartment being connectable with a motivated quantity of fluid through the other of said openings in the casing, one of said diaphragms having a larger area subjected to fluid than the other, said diaphragms being spaced from one another,

2. a spacing portion between said diaphragms and being disposed in the space between the diaphragms;

E. a spring effecting pressure on the integral element, said spring being disposed in the space between the diaphragms;

F. means carried by the casing and engaging the spring, said means extending through the casing and movable from the exterior of the casing for adjusting the effective pressure of the spring.

2. A controller as defined in claim 1, characterized in that the confronting walls of the diaphragms cooperate with the casing and form a compartment between the diaphragms.

3. A controller as defined in claim 1, characterized in that the casing includes:

A. 3. a ring,

4. a cup connected with the ring and cooperating with one of the diaphragms to form one of said compartments.

4. A controller as defined in claim 3, characterized in that the casing includes:

A. 5. a second cup connected with the ring and cooperating with the other diaphragm to form the other of said compartments.

5. A controller as defined in claim 3, characterized in that the means (F) is carried by the ring.

6. A controller as defined in claim 4, characterized in that the ring and the diaphragms form a unit.

7. A controller as defined in claim 4, characterized in that the ring and the two diaphragms form a compartment between the diaphragms.

8. A controller as defined in claim 7, characterized in that the outer faces of the diaphragms are sealingly fastened between the ring and the cups.

9. A controller as defined in claim 7, characterized in that the means (F) is carried by the ring.